Input: wacom - separate pen from express keys on Graphire

[safe/jmp/linux-2.6] / drivers / input / input.c

diff --git a/drivers/input/input.c b/drivers/input/input.c
index cc763c9..ab06071 100644 (file)
--- a/drivers/input/input.c
+++ b/drivers/input/input.c
@@ -296,9 +296,15 @@ static void input_handle_event(struct input_dev *dev,
  * @value: value of the event
  *
  * This function should be used by drivers implementing various input
- * devices. See also input_inject_event().
+ * devices to report input events. See also input_inject_event().
+ *
+ * NOTE: input_event() may be safely used right after input device was
+ * allocated with input_allocate_device(), even before it is registered
+ * with input_register_device(), but the event will not reach any of the
+ * input handlers. Such early invocation of input_event() may be used
+ * to 'seed' initial state of a switch or initial position of absolute
+ * axis, etc.
  */
-
 void input_event(struct input_dev *dev,
                 unsigned int type, unsigned int code, int value)
 {
@@ -1292,17 +1298,24 @@ static int input_dev_uevent(struct device *device, struct kobj_uevent_env *env)
        return 0;
 }
 
-#define INPUT_DO_TOGGLE(dev, type, bits, on)                   \
-       do {                                                    \
-               int i;                                          \
-               if (!test_bit(EV_##type, dev->evbit))           \
-                       break;                                  \
-               for (i = 0; i < type##_MAX; i++) {              \
-                       if (!test_bit(i, dev->bits##bit) ||     \
-                           !test_bit(i, dev->bits))            \
-                               continue;                       \
-                       dev->event(dev, EV_##type, i, on);      \
-               }                                               \
+#define INPUT_DO_TOGGLE(dev, type, bits, on)                           \
+       do {                                                            \
+               int i;                                                  \
+               bool active;                                            \
+                                                                       \
+               if (!test_bit(EV_##type, dev->evbit))                   \
+                       break;                                          \
+                                                                       \
+               for (i = 0; i < type##_MAX; i++) {                      \
+                       if (!test_bit(i, dev->bits##bit))               \
+                               continue;                               \
+                                                                       \
+                       active = test_bit(i, dev->bits);                \
+                       if (!active && !on)                             \
+                               continue;                               \
+                                                                       \
+                       dev->event(dev, EV_##type, i, on ? active : 0); \
+               }                                                       \
        } while (0)
 
 #ifdef CONFIG_PM
@@ -1651,6 +1664,38 @@ void input_unregister_handler(struct input_handler *handler)
 EXPORT_SYMBOL(input_unregister_handler);
 
 /**
+ * input_handler_for_each_handle - handle iterator
+ * @handler: input handler to iterate
+ * @data: data for the callback
+ * @fn: function to be called for each handle
+ *
+ * Iterate over @bus's list of devices, and call @fn for each, passing
+ * it @data and stop when @fn returns a non-zero value. The function is
+ * using RCU to traverse the list and therefore may be usind in atonic
+ * contexts. The @fn callback is invoked from RCU critical section and
+ * thus must not sleep.
+ */
+int input_handler_for_each_handle(struct input_handler *handler, void *data,
+                                 int (*fn)(struct input_handle *, void *))
+{
+       struct input_handle *handle;
+       int retval = 0;
+
+       rcu_read_lock();
+
+       list_for_each_entry_rcu(handle, &handler->h_list, h_node) {
+               retval = fn(handle, data);
+               if (retval)
+                       break;
+       }
+
+       rcu_read_unlock();
+
+       return retval;
+}
+EXPORT_SYMBOL(input_handler_for_each_handle);
+
+/**
  * input_register_handle - register a new input handle
  * @handle: handle to register
  *
@@ -1683,7 +1728,7 @@ int input_register_handle(struct input_handle *handle)
         * we can't be racing with input_unregister_handle()
         * and so separate lock is not needed here.
         */
-       list_add_tail(&handle->h_node, &handler->h_list);
+       list_add_tail_rcu(&handle->h_node, &handler->h_list);
 
        if (handler->start)
                handler->start(handle);
@@ -1706,7 +1751,7 @@ void input_unregister_handle(struct input_handle *handle)
 {
        struct input_dev *dev = handle->dev;
 
-       list_del_init(&handle->h_node);
+       list_del_rcu(&handle->h_node);
 
        /*
         * Take dev->mutex to prevent race with input_release_device().
@@ -1714,6 +1759,7 @@ void input_unregister_handle(struct input_handle *handle)
        mutex_lock(&dev->mutex);
        list_del_rcu(&handle->d_node);
        mutex_unlock(&dev->mutex);
+
        synchronize_rcu();
 }
 EXPORT_SYMBOL(input_unregister_handle);